$string['uploadextension']: ambiguous statement in EN lang pack

The string currently used in case of UPLOAD_ERR_EXTENSION:

$string['uploadextension'] = 'File upload stopped by extension'

can lead to kind of misunderstandings, the user can think at the file extension rather than to a PHP extension.
It should be something like:

$string['uploadextension'] = 'File upload stopped by a PHP extension'

according with http://php.net/manual/en/features.file-upload.errors.php:

UPLOAD_ERR_EXTENSION

Value: 8; A PHP extension stopped the file upload. PHP does not provide a way to ascertain which extension caused the file upload to stop; examining the list of loaded extensions with phpinfo() may help. Introduced in PHP 5.2.0.